The offices of the United Nations in the city of Herat in western Afghanistan, where clashes are taking place between the Taliban and Afghan forces, were attacked on Friday, as announced by the International Organization for Assistance to Afghanistan. 

The mission said in a statement, "This attack on the entrance to a building that clearly appears to belong to the United Nations, was carried out by anti-government elements," noting that an Afghan policeman who was guarding the building was killed and others wounded.

It added that the entrance to the complex came under fire from rocket launchers and artillery, and no United Nations staff were injured.

According to the statement, the area where the offices were attacked witnessed clashes between the Taliban and government forces on Friday.

"This attack on the United Nations is unfortunate, and we condemn it in the strongest terms," the statement quoted Deborah Lyons, the special representative of the United Nations Secretary-General in Afghanistan and head of mission in the country, as saying. She said, "the identity of the perpetrators of this attack must be identified and held accountable."

Attacks against civilians and UN premises are prohibited under international law and may constitute war crimes, the mission said, praising the Afghan guards who defended the UN compound from the militants.

Taliban gunmen clashed with government forces on the outskirts of Herat on Friday, forcing dozens of families to flee, residents said, as insurgents closed in on the western Afghan city.

The Taliban took control of many areas on the outskirts of the city, as well as two border crossings in Herat Province, bordering Iran and Turkmenistan, while continuing to advance throughout the country.

Violence has escalated since early May when US-led foreign forces began their final withdrawal, which is nearing completion.

Afghan forces and militias loyal to the veteran warlord and anti-Taliban leader Ismail Khan have deployed around the city of 600,000.